Error loading method handleRequest for RequestHandler<APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent>

1

I am using LocalStack Community to try a lambda to be called by an API Gateway.

import java.util.Map;
import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent;
import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyResponseEvent;

public class HandlerHelloGateway implements RequestHandler<APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent> {
    @Override
    public APIGatewayProxyResponseEvent handleRequest(APIGatewayProxyRequestEvent event, Context context) {
        String helloValue = event.getQueryStringParameters() != null ? event.getQueryStringParameters().get("hello")
                : "default value";
        String responseBody = String.format("{\"message\": \"Input was: %s\"}", helloValue);
        return new APIGatewayProxyResponseEvent()
                .withStatusCode(200)
                .withHeaders(Map.of("Content-Type", "application/json"))
                .withBody(responseBody);
    }
}

I created a zip:

HandlerHelloGateway.zip: hellocucumber-1.0.0-SNAPSHOT.jar
	cp target/classes/HandlerHelloGateway.class .
	cp target/hellocucumber-1.0.0-SNAPSHOT.jar .
	zip -r HandlerHelloGateway.zip hellocucumber-1.0.0-SNAPSHOT.jar HandlerHelloGateway.class
	rm HandlerHelloGateway.class hellocucumber-1.0.0-SNAPSHOT.jar

Then create the lambda by:

awslocal lambda create-function --function-name HandlerHelloGateway \
    --zip-file fileb://HandlerHelloGateway.zip \
    --handler HandlerHelloGateway::handleRequest \
    --runtime java21 \
    --role arn:aws:iam::123456789012:role/lambda-execution-role

call this lambda by:

awslocal lambda invoke --function-name HandlerHelloGateway output.txt --cli-binary-format raw-in-base64-out --payload '"hello"'

Output.txt shows “Error loading method handleRequest on class HandlerHelloGateway”.

If I replace the above lambda function with the below code, then Output.txt shows the expected result.

public class HandlerHelloGateway implements RequestHandler<String, String> {
   @Override
   public String handleRequest(String input, Context context) {
    return "Hello from LocalStack Lambda! Input was: " + input;
  }
}

Any idea why the lambda implementing RequestHandler<APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent> does not work? Is it not supported by LocalStack Community? Thanks very much!